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Rinehart CA, Chen KY. Characterization of the polyamine transport system in mouse neuroblastoma cells. Effects of sodium and system A amino acids. J Biol Chem 1984; 259:4750-6. [PMID: 6715320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The biochemical properties of polyamine transport system have been studied in detail in NB-15 mouse neuroblastoma cells in culture by measuring the uptake of [14C]putrescine under various experimentally imposed pharmacological conditions. Putrescine uptake in the NB-15 mouse neuroblastoma cells appeared to be a sodium-dependent process. Iso-osmotic displacement of Na+ in the assay medium with either choline or Li+ resulted in a linear decrease of putrescine uptake. Gramicidin, a channel-former ionophore, inhibited putrescine uptake by more than 90% at 20 nM. N-Ethylmaleimide at 5 mM or p-chloromercuribenzene sulfonate at 50 microM completely abolished putrescine uptake. Conversely, oxidized glutathione at 10 mM or 5,5'-dithiobis-(2-nitrobenzoic acid) at 5 microM gave a 1.3-1.4-fold stimulation after a 1-h incubation. This polyamine transport system appeared to be subjected to adaptive regulation. Polyamine antimetabolites such as alpha-difluoromethyl ornithine stimulated putrescine uptake whereas preloading of cells with polyamines inhibited putrescine uptake. Preloading cells with neutral amino acids that belong to sodium-dependent transport System A stimulated putrescine uptake by more than 8-10-fold. These results suggested that the polyamine transport system in NB-15 mouse neuroblastoma cells was sodium dependent and shared some characteristics common to other known sodium-dependent transport systems. These characteristics included (a) sensitivity to ionophores, (b) sensitivity to sulfhydryl reagents, and (c) sensitivity to intracellular contents of substrate molecules. Our data also indicated that polyamine transport may be regulated by transport System A amino acids.
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Rinehart CA, Chen KY. Characterization of the polyamine transport system in mouse neuroblastoma cells. Effects of sodium and system A amino acids. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)42910-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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228
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Chen KY, Verma R. Spermine specifically inhibits the phosphorylation of an 11,000-dalton nuclear protein in various cultured mammalian cell lines. Biochem Biophys Res Commun 1984; 118:710-6. [PMID: 6704103 DOI: 10.1016/0006-291x(84)91452-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The effect of polyamines (putrescine, spermidine and spermine) on endogenous protein phosphorylation in mouse neuroblastoma cells was investigated by using techniques of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The results indicated that spermine at 1mM completely inhibited the phosphorylation of the 11,000-dalton and 120,000-dalton proteins in nuclear fractions. The inhibition of the phosphorylation of the 11,000-dalton but not the 120,000-dalton protein by spermine was also observed in five other cell lines examined and appeared to be a general phenomenon. The inhibitory effect of spermine on the phosphorylation of the 11,000-dalton protein was specific, other cations such as ammonium chloride, arginine, putrescine, cyclen and trien were ineffective at equal molar or much higher concentrations.
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Chen KY. Transglutaminase catalyzed incorporation of putrescine into surface proteins of mouse neuroblastoma cells. Mol Cell Biochem 1984; 58:91-7. [PMID: 6143257 DOI: 10.1007/bf00240608] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Transglutaminase, purified from guinea pig liver, was used to catalyze the incorporation of [14C]putrescine into exposed surface proteins of intact mouse neuroblastoma cells. This method specifically labeled two surface proteins (Mr = 92 000 and 76 000) in the N-18 mouse neuroblastoma cells and three surface proteins (Mr = 92 000, 76 000, and 72 000) in the NB-15 mouse neuroblastoma cells. In addition, transglutaminase also catalyzed cross-linking reactions of exposed surface proteins. In both the N-18 and NB-15 cells, differentiation was accompanied by a 2-fold increase of specific radioactivity incorporated into trichloroacetic acid insoluble cellular material, suggesting that the differentiated mouse neuroblastoma cells may possess greater amount of accessible peptide-bound glutaminyl residues on their surface than their malignant counterparts. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorographic method revealed that while the [14C]putrescine-labeled protein patterns of undifferentiated and differentiated mouse neuroblastoma cells were similar, the intensity of labeling of individual bands was specifically modulated by cell differentiation.
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Chen KY, Wen SF, Zhi ZJ, Shao JS. Preliminary observation of 131Cs distribution in experimental acute myocardial infarction and coronary insufficiency treated with root of salvia miltiorrhiza, flower of Chrysanthemum morifolium and Chrysanthemum indicum. J TRADIT CHIN MED 1983; 3:265-70. [PMID: 6562297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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231
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Chen KY, Lin BY, Zhang JX, Shao BR. [7 antimalarials in the treatment of mice experimentally infected with pyronaridine-resistant Plasmodium berghei]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1983; 4:269-73. [PMID: 6230874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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232
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Wilkins JA, Chen KY, Lin S. Detection of high molecular weight vinculin binding proteins in muscle and nonmuscle tissues with an electroblot-overlay technique. Biochem Biophys Res Commun 1983; 116:1026-32. [PMID: 6418169 DOI: 10.1016/s0006-291x(83)80245-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In this study, we examined binding of radiolabelled vinculin to proteins separated on sodium dodecyl sulfate-polyacrylamide gels, and then electrophoretically transferred onto nitrocellulose sheets. We detected saturable binding of vinculin to polypeptides with apparent Mr's of 215,000, 205,000 and 185,000 in a low ionic strength extract from chicken gizzard membranes. Binding of vinculin to proteins with apparent Mr's of 205,000, 185,000, and 165,000 in human platelets was also detected. In addition, we found that [125I]vinculin binds to unlabelled vinculin and to alpha-actinin, although these interactions appear to be of lower affinity than those with the higher molecular weight proteins.
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Tseng CY, Chen PH, Lin SC, Lo HW, Wang CS, Lee LS, Siauw CP, Chen KY, Liu MH. [Primary hyperlipoproteinemia type V complicated by acute pancreatitis]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:1082-7. [PMID: 6582226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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234
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Chen KY, Chen GP, Feng X. Observation of immediate effect of acupuncture on electroencephalograms in epileptic patients. J TRADIT CHIN MED 1983; 3:121-4. [PMID: 6555444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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235
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Chen KY, Nau D, Liu AY. Effects of inhibitors of ornithine decarboxylase on the differentiation of mouse neuroblastoma cells. Cancer Res 1983; 43:2812-8. [PMID: 6303569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
(R, S)-alpha-Fluoromethylornithine (alpha-FMO), a catalytic irreversible inhibitor of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17), induced the differentiation of N2a mouse neuroblastoma cells. The effect of alpha-FMO was concentration dependent; approximately 50% of the cell population exhibited neurite outgrowth in the presence of 1 mM alpha-FMO, while higher concentrations caused severe growth inhibition and cell death. The effect of 1 mM alpha-FMO on neuroblastoma differentiation was potentiated greatly by 0.1 to 0.2 mM N6,O2'-dibutyryl adenosine cyclic 3':5'-monophosphate (Bt2cAMP) causing more than 90% of the cell population to differentiate morphologically with thick and long processes; 0.1 to 0.2 mM Bt2cAMP, by itself, had no effect on cell growth and did not induce neurite outgrowth. The effect of alpha-FMO, either by itself or in combination with 0.1 to 0.2 mM Bt2cAMP, on the morphological differentiation of mouse neuroblastoma cells was reversed by the addition of exogenous putrescine or spermidine. The morphological differentiation of mouse neuroblastoma cells induced by 1 mM alpha-FMO plus 0.2 mM Bt2cAMP was accompanied by increases of the regulatory subunit of the type I cAMP-binding protein and acetylcholinesterase activity. These results indicate that the modulation of cellular polyamine contents may be important in neuroblastoma cell differentiation.
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Chen KY. An 18000-dalton protein metabolically labeled by polyamines in various mammalian cell lines. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 756:395-402. [PMID: 6830862 DOI: 10.1016/0304-4165(83)90350-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The possible role of polyamines in the covalent modification of cellular protein(s) was investigated by studying the metabolic labeling of NB-15 mouse neuroblastoma cells by [14C]putrescine in fresh Dulbecco's medium followed by separation of cellular proteins through sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Under such incubation conditions, a single protein band with an apparent molecular weight of 18000 was radioactively labeled. [14C]Spermidine also specifically labeled this protein. The majority of the radioactivity covalently linked to the 18-kDa protein was recovered as hypusine. The radioactive labeling of this protein was stimulated 1.3-fold by 1 mM dibutyryl cAMP and 2.8-fold by 4% fetal calf serum. Fetal calf serum also stimulated the labeling of many other cellular proteins. This may be due to the conversion of putrescine to amino acids via the formation of gamma-aminobutyric acid. Aminoguanidine, a potent inhibitor of diamine oxidase, completely inhibited the fetal calf serum-stimulated labeling of these cellular proteins but had no effect on the labeling of the 18-kDa protein. The specific labeling of the 18-kDa protein by [14C]putrescine occurred in various mammalian cells examined including the N-18 mouse neuroblastoma cells, 3T3-L1 murine preadipocytes, and H-35 rat hepatoma cells. The specificity of labeling of the apparently ubiquitous 18-kDa protein and the stimulation of this labeling by fetal calf serum suggest that this protein may be important in mediating some of the actions of polyamines in cell growth regulation.
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Chen XR, Ni XY, Huang RX, Wang ZY, Gu J, Lin G, Zhang ZN, Fan MY, Lin SC, Xu JB, Shi WJ, Wang MK, Wu S, Wu PS, Wang BH, Zhang BY, Zhou MF, Guo YZ, Li CM, Chen KY, He YT, Guo LX, Ju CQ. [Percutaneous transhepatic cholangiography and drainage]. ZHONGHUA FANG SHE XUE ZA ZHI CHINESE JOURNAL OF RADIOLOGY 1983; 17:33-7. [PMID: 6224659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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238
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Chen KY, Liu AY. Differences in the mode of regulation of ornithine decarboxylase and tyrosine aminotransferase in H-35 rat hepatoma cells shown by varying the medium composition. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 755:244-52. [PMID: 6131694 DOI: 10.1016/0304-4165(83)90210-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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239
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Viceps-Madore D, Chen KY, Tsou HR, Canellakis ES. Studies on the role of protein synthesis and of sodium on the regulation of ornithine decarboxylase activity. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 717:305-15. [PMID: 7115771 DOI: 10.1016/0304-4165(82)90184-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The minimum requirements for eliciting or enhancing ornithine decarboxylase activity (EC. 4.1.1.17); L-ornithine carboxylase) in neuroblastoma cells incubated in salts-glucose solutions have been investigated. These incubation conditions permit the study of changes in ornithine decarboxylase activity independently of the growth-associated reactions that occur in cell culture media (Chen, K.Y. and Canellakis, E.S. (1977) Proc. Natl, Acad. Sci. U.S.A. 74, 3791-3795). Ornithine decarboxylase activity can be elicited by a variety of asparagine and other amino acid analogs, including alpha-aminoisobutyric acid, that cannot participate in protein synthesis. Of the eleven asparagine analogs tested, alpha-N-CH3-DL-asparagine is the most potent in eliciting ornithine decarboxylase activity and is equivalent to asparagine in this regard. Inclusion of polar groups into the asparagine molecule results in the loss of its ability to elicit ornithine decarboxylase activity. With the use of these analogs and of analogs of other amino acids it is shown that the rapid fall in ornithine decarboxylase activity that is noted following cycloheximide treatment may not be a consequence of the inhibition of protein synthesis. The rapid fall in ornithine decarboxylase activity is primarily due to the removal of the agent that elicits and stabilizes its activity. These results, the finding that alpha-aminoisobutyric acid stimulates ornithine decarboxylase activity and that sodium is required for the stimulation of ornithine decarboxylase activity are discussed in relation to the "A" amino acid transport system.
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Gray RF, Schindler RA, Chen KY, Wang ZZ, Wilson F. Response of the endolymphatic sac in the guinea pig to neomycin ototoxicity. Am J Otolaryngol 1982; 3:254-61. [PMID: 6983307 DOI: 10.1016/s0196-0709(82)80063-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The guinea pig provides an excellent model for studying the effects of ototoxic antibiotics on the epithelium of the endolymphatic sac (ELS). Intracochlear injection of neomycin produces consistent destruction of cochlear and vestibular sensory cells, and the response to this traumatic insult can be documented by light and electron microscopy of the ELS. The histologic findings suggest that ELS epithelial cells are relatively resistant to ototoxic levels of neomycin. The study confirms the ability of the ELS to increase its activity during periods of labyrinthine stress.
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Chen KY, Kyriakidis DA, Canellakis ES. The inhibition of the serum-stimulated increase of ornithine decarboxylase by ionophores and local anesthetics. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 716:72-8. [PMID: 7093304 DOI: 10.1016/0304-4165(82)90204-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The addition of fresh serum-containing growth medium to L1210 mouse leukemic cells in culture resulted in a 5-fold increase in ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) activity. The presence of microtubule disrupting agents (colchicine, vinblastine) or cations (5-10 mM K+, Na+ or Mg2+) abolishes this increase of ornithine decarboxylase activity. (Chen, K.Y., Heller, J.S. and Canellakis, E.S. (1976) Biochem. Biophys. Res. Commun. 70, 212-219). Based on these observations we proposed that fluctuation in cellular cation concentrations may act as a link between the membrane structure and ornithine decarboxylase. To test this proposal, we studied the effects of selective membrane perturbing agents such as ionophores and local anesthetics, on the serum-stimulated increase of ornithine decarboxylase activity in L1210 cells. Among the six ionophores tested, valinomycin was the most potent one, with I50 value (concentration that gives 50% inhibition of ornithine decarboxylase activity) of 6.10(-9) M. Dibucaine and tetracaine were also effective inhibitors at 10(-4)-10(-5) M. The I50 values of valinomycin on the protein synthesis and RNA synthesis, however, were greater than 1.10(-6) M. These results substantiate the notion that ornithine decarboxylase activity can be regulated at plasma membrane level and such regulation is related to the perturbation of cellular cation pools.
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242
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Chen KY, Presepe V, Parken N, Liu AY. Changes of ornithine decarboxylase activity and polyamine content upon differentiation of mouse NB-15 neuroblastoma cells. J Cell Physiol 1982; 110:285-90. [PMID: 6282899 DOI: 10.1002/jcp.1041100311] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The possible functions of ornithine decarboxylase (ODC) and polyamines in the differentiation of mouse NB-15 neuroblastoma cells were investigated by examining the changes of these parameters in the differentiating and nondifferentiating NB-15 cells over a 5-day culture period. Differentiation of NB-15 cells was induced by the addition of dibutyryl cyclic AMP and 3-isobutyl-1-methylxanthine (1BMX) to the growth medium and was monitored by neurite outgrowth, increases of acetylcholinesterase (AChE), and RI cAMP-binding protein. Plating of NB-15 cells in fresh serum-containing growth medium was accompanied by rapid growth and a marked increase of ODC activity; this early increase of ODC activity was attenuated, both in duration and in magnitude, in the differentiating cells. The spermidine content of the differentiating neuroblastoma cells was significantly lower than that of the nondifferentiating cells. In the fully differentiated neuroblastoma cells, the ODC activity and spermidine content were lower than that of the undifferentiated cells by approximately 15-fold and five-fold, respectively. Based on these results it is proposed that changes of polyamine metabolism may be of significance in the differentiation of mouse neuroblastoma cells.
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243
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Chen KY, Rinehart CA. Identification of exposed surface glycoproteins in undifferentiated and differentiated mouse N-18 neuroblastoma cells. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 685:61-70. [PMID: 7059592 DOI: 10.1016/0005-2736(82)90035-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A simple method is described that permitted rapid isolation of plasma membranes from mouse N-18 neuroblastoma cells. The purified plasma membranes gave a 10-fold increase in the specific activity of incorporated [3H]fucose over that of the cell homogenate. The specific activities of two other membrane markers, 5'-nucleotidase and alkaline phosphatase, increased 11-fold and 15-fold, respectively. Metabolic labeling with [3H]fucose identified a major fucosyl glycoprotein with apparent molecular weight of 92 000. Three surface labeling methods together with SDS-polyacrylamide gel electrophoresis and fluorography were used to characterize and compare the surface glycoproteins of undifferentiated and differentiated N-18 cells. The galactose oxidase/NaB3H4 method labeled two major galactoproteins (Mr = 52 000, 42 000) in both undifferentiated and differentiated cells. The neuraminidase/galactose oxidase/NaB3H4 method revealed many sialylgalactoproteins. Among them, the 220-kdalton, 150-kdalton and 130-kdalton bands were at least 100% more prominently labeled in the differentiated cells whereas the 76-kdalton and 72-kdalton bands were less prominently labeled in the differentiated cells when compared to their undifferentiated counterparts. The prominently iodinated protein bands in the undifferentiated cells had apparent molecular weights of 130 000, 92 000, 76 000 and 72 000 as compared to 150-, 130-, 92- and 76-kdalton bands in the differentiated cells. The labeling data obtained will enable us to further study the changes of these identified surface glycoproteins, both quantitatively and topologically, during the differentiation of neuroblastoma cells.
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Chen KY, Liu AY. Differences in polyamine metabolism of the undifferentiated and differentiated neuroblastoma cells. Metabolic labeling of an 18,000-M(r) protein by [14C]putrescine and the conversion of putrescineto GABA. FEBS Lett 1981; 134:71-4. [PMID: 9222327 DOI: 10.1016/0014-5793(81)80553-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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245
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Liu AY, Chan T, Chen KY. Induction of the regulatory subunit of type I adenosine cyclic 3':5'-monophosphate-dependent protein kinase in differentiated N-18 mouse neuroblastoma cells. Cancer Res 1981; 41:4579-87. [PMID: 6272981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The expression of a adenosine cyclic 3':5'-monophosphate (cAMP)-binding protein, regulatory subunit of the type I cAMP-dependent protein kinase (Rl), and its functional significance in the differentiation of N-18 mouse neuroblastoma cells were examined. 8-Azidoadenosine cyclic 3':5'-[32P]monophosphate, a photoaffinity-labeling analog of cAMP, and high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to identify and quantitate cAMP-binding proteins in cell extracts. The induction of differentiation of N-18 mouse neuroblastoma cells, initiated either by adding dibutyryl adenosine cyclic 3':5'-monophosphate to the growth medium or by culturing cells in medium supplemented with 1% fetal calf serum, led to a 3-fold increase in the amount of 8-azidoadenosine cyclic 3':5'-[32P]monophosphate incorporated into Rl, when assayed in vitro. This increased incorporation was attributable to an increase in the amount of Rl rather than to an increase in the affinity of Rl for 8-azidoadenosine cyclic 4':5'-[32P]monophosphate. The subunit molecular weight, isoelectric point, and immunoreactivity of Rl were found to be identical to that of the regulatory subunit of the type I cAMP-dependent protein kinase purified from bovine skeletal muscle. The increase in Rl was not accompanied by an increase in the cAMP-dependent protein kinase activity. DEAE-cellulose column chromatography confirmed the induction of Rl as a free cAMP-binding protein in the differentiated neuroblastoma cells. The possibility of a growth-dependent regulation of Rl was also examined. Addition of 2% dimethyl sulfoxide to cultures of N-18 mouse neuroblastoma cells inhibited cell growth without increasing the specific activity of Rl. Dimethyl sulfoxide had no effect on neurite outgrowth or acetylcholinesterase activity, two parameters characteristic of differentiated cells. The fact that the induction of Rl coincided with differentiation of the neuroblastoma cells suggests that the expression of Rl may be used as a biochemical index of differentiation in these cells. The presence of a free cAMP-binding protein, not associated with cAMP-dependent protein kinase in neuroblastoma cells, raises important considerations concerning the action of cAMP in the regulation of growth and differentiation.
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Jame JM, Chen CN, Chen KY. Importance of early diagnosis and radiotherapy in spinal cord compression by metastatic neoplasms. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1981; 80:1178-85. [PMID: 6948912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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247
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Chen KY, Rinehart CA. Difference in putrescine transport in undifferentiated versus differentiated mouse NB-15 neuroblastoma cells. Biochem Biophys Res Commun 1981; 101:243-9. [PMID: 6269547 DOI: 10.1016/s0006-291x(81)80037-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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248
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Jame JM, Wang CI, Jan JS, Chen KY. Primary mediastinal seminoma: 2 cases report and review of the literature. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1981; 80:271-9. [PMID: 6942113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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249
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Liu AY, Fiske WW, Chen KY. Regulation of cyclic adenosine 3':5'-monophosphate-binding protein in N-18 mouse neuroblastoma cells. Cancer Res 1980; 40:4100-8. [PMID: 6258772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The regulation of cyclic adenosine 3':5'-monophosphate (cAMP)-binding protein in N-18 neuroblastoma cells in tissue culture was studied by the covalent incorporation of 8-azido-cyclic adenosine 3':5'-[32P]monophosphate, together with the techniques of sodium dodecyl sulfate:polyacrylamide gel electrophoresis and autoradiography. Greater than 95% of the total cAMP binding activity of N-18 neuroblastoma cells was identified as being regulatory subunits of the type I (RI) and type II (RII) species, with RI being the predominant form of the two (RI:RII = 3:1). The specific activity of RI but not of RII increased 3-fold when cells were grown in medium containing 1% rather than 10% fetal calf serum. Under the same conditions, the specific activity of acetylcholinesterase increased 3- to 5-fold. The increase in RI was inversely related to the serum concentration in the medium and was specific for cells at the stationary phase of growth. An increase in intracellular cAMP, concomitant with the increase in RI, was also observed. Morphological examination of stationary-phase neuroblastoma cells maintained in medium containing 1% fetal calf serum suggested the presence of a high proportion of highly-differentiated cells. It is proposed that the regulatory control of RI cAMP-binding protein by serum may involve modulation of intracellular cAMP and that the expression RI may be used as a biochemical index of differentiation in mouse neuroblastoma cells.
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Chen KY. Differences in the mode of regulation of ornithine decarboxylase activity in undifferentiated versus differentiated mouse N-18 neuroblastoma cells. FEBS Lett 1980; 119:307-11. [PMID: 6253326 DOI: 10.1016/0014-5793(80)80278-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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